首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
The exact pro-oxidant and antioxidant status in pregnancy--induced hypertension patients is still not clear. To add a new insight to the question, changes in the erythrocyte lipid peroxidation products (malondialdehyde; MDA), levels of glutathione (GSH), ascorbic acid and plasma vitamin E (non enzymatic antioxidant parameters) and activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase in erythrocytes were studied in thirty five patients with pregnancy--induced hypertension and thirty five healthy pregnant normotensive cases. It was observed that there was a significant increase in erythrocyte MDA levels, activities of SOD, GPx and a significant decrease in erythrocyte GSH, ascorbic acid, plasma vitamin E levels and catalase activity in patients with pregnancy--induced hypertension when compared to controls. The results of our study have shown higher oxygen free radical production, evidenced by increased levels of MDA and decreased levels of GSH, ascorbic acid, vitamin E and Catalase activity supports the oxidative stress in pregnancy--induced hypertension. The increased activities of antioxidant enzymes may be a compensatory regulation in response to increased oxidative stress. The decreased concentrations of glutathione and antioxidant vitamin status supports the hypothesis that lipid peroxidation is an important causative factor in the pathogenesis of preeclampsia.  相似文献   

2.
This study was designed to investigate the possible protective effects of antioxidants (vitamin E, beta-carotene, vitamin C, and red ginseng) on lipid peroxidation in smokers (> or = 20 cigarettes/day). Male student smokers were given antioxidant supplements for 4 wk. Smokers had significantly higher plasma levels of total cholesterol, triacylglycerols, and malondialdehyde (MDA) than nonsmokers. No corresponding significant differences in lipid profiles were found between smokers and nonsmokers. Smokers had significantly lower baseline concentrations of plasma vitamin C, beta-carotene, and alpha-tocopherol. After antioxidant (200 IU vitamin E, 9 mg beta-carotene, 500 mg vitamin C, or 1.8 g red ginseng) supplementation for 4 wk, smokers had significantly higher concentrations of plasma antioxidants. After 4 wk of antioxidant supplementation with betacarotene, high-density lipoprotein (HDL) cholesterol concentrations in smokers were significantly increased. Overall, plasma MDA concentrations gradually decreased after antioxidant supplementation over the 4-wk period. Moreover, a significant reduction in plasma MDA concentrations was observed after vitamin E supplementation. The results of our study support the hypothesis that lipid peroxidation concentrations are inversely correlated with plasma antioxidant concentrations. Our data suggest that smokers have insufficient concentrations of antioxidant vitamins in plasma and that supplementation with antioxidants might protect smokers from oxidative damage.  相似文献   

3.
The mechanisms of the liver damage produced by three glutathione (GSH) depleting agents, bromobenzene, allyl alcohol and diethylmaleate, was investigated. The change in the antioxidant systems represented by alpha-tocopherol (vitamin E) and ascorbic acid were studied under conditions of severe GSH depletion. With each toxin liver necrosis was accompanied by lipid peroxidation that developed only after severe depletion of GSH. The hepatic level of vitamin E was decreased whenever extensive lipid peroxidation developed. In the case of bromobenzene intoxication, vitamin E decreased before the onset of lipid peroxidation. Changes in levels of the ascorbic and dehydroascorbic acid indicated a redox cycling of vitamin C with the oxidative stress induced by all the three agents. Such a change of the redox state of vitamin C (increase of the oxidized over the reduced form) may be an index of oxidative stress preceding lipid peroxidation in the case of bromobenzene. In the other cases, such a change is likely to be a consequence of lipid peroxidation. Experiments carried out with vitamin E deficient or supplemented diets indicated that the pathological phenomena occurring as a consequence of GSH depletion depend on hepatic levels of vitamin E. In vitamin E deficient animals, lipid peroxidation and liver necrosis appeared earlier than in animals fed the control diet. Animals fed a vitamin E supplemented diet had an hepatic vitamin E level double that obtained with a commercial pellet diet. In such animals, bromobenzene and allyl alcohol had only limited toxicity and diethylmaleate none in spite of comparable hepatic GSH depletion. Thus, vitamin E may largely modulate the expression of the toxicity by GSH depleting agents.  相似文献   

4.
The present study was aimed to investigate the effect of Casearia esculenta root extract on erythrocyte lipid peroxidation and to assess the status of antioxidants in red blood cells of streptozotocin (STZ) diabetic rats. The study showed a significant elevation (p < 0.05) of erythrocyte thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation and significant reduction (p < 0.05) in reduced glutathione (GSH), ascorbic acid (vitamin C), alpha-tocopherol (vitamin E), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in the STZ diabetic rats. The study also observed significant reduction in membrane cholesterol and phospholipid content in STZ diabetic rats. By oral administration of C. esculenta (200 and 300 mg/kg body wt.) for 45 days to the diabetic rats these values approached almost normal levels. A dose of 300 mg/kg body weight C. esculenta extract showed better antioxidant effects than 200 mg/kg body weight.  相似文献   

5.
A K De  R Darad 《Toxicology letters》1988,44(1-2):47-54
The effects of feeding vitamin E-deficient diets to rats for one year were investigated to analyse the relationship of the vitamin with other antioxidants and some antioxidative enzymes. Long-term vitamin E deficiency lowered the levels of antioxidants like vitamin E, ascorbic acid and glutathione (GSH) in all tissues analysed and thus increasing the extent of tissue peroxidisability. Vitamin E deficiency had also influenced the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase, the enzymes that are involved in detoxification mechanisms of products arising from free radical metabolism.  相似文献   

6.
Acute effects of cadmium (Cd) and combined antioxidants were evaluated in Sprague–Dawley rat testes. The rats were subdivided into four groups. Cadmium chloride (2 mg/kg day) injected intraperitoneally during 8 days. Vitamin C (250 mg/kg day), vitamin E (250 mg/kg day) and sodium selenate (0.25 mg/kg day) were pretreated by gavage in both of control and cadmium injected rats. Testis lipid peroxidation and glutathione levels were determined by spectrophotometrically. In Cd treated rats, lipid peroxidation levels were increased and glutathione levels were decreased and combined antioxidants treatment was effective in preventing of lipid peroxidation and normalizing glutathione. In Cd treated animals, the degenerative changes were observed, but not observed in the administrated rats with Cd and antioxidants under the light microscope. Proliferating cell nuclear antigen, metallothionein and caspase-3 activities were evaluated by immunohistochemically. Proliferation activity was not seen in the spermatogonial cells of cadmium treated testis. Treatment with antioxidants in cadmium administrated testis leads to pronounced increase in proliferation activity. Cytoplasmic caspase-3 activity was determined in the spermatogenic cells but not spermatogonia in treatment of antioxidants with Cd. In control and treated with antioxidants animals, metallothionein expressions were localized in the cells of seminiferous tubules, although the expression only was observed in the interstitial cells of cadmium treated rats. Results demonstrated beneficial effects of combined vitamin C, vitamin E and selenium treatment in Cd toxicity.  相似文献   

7.
The pharmacological effects of melatonin, vitamin E, vitamin C, glutathione and desferrioxamine (desferoxamine) alone and in combination on iron-induced membrane lipid damage in rat liver homogenates were examined by estimating levels of malondialdehyde and 4-hydroxyalkenals (MDA+4-HDA). Individually, melatonin (2.5-1600 microM), vitamin E (0.5-50 microM), glutathione (100-7000 microM) and desferrioxamine (1-8 microM) inhibited lipid peroxidation in a concentration-dependent manner. Vitamin C had both a pro-oxidative (25-2000 microM) and an antioxidative (2600-5000 microM) effect. The IC50 (concentration that reduces damage by 50%) values were 4, 10, 426, 2290 and 4325 microM for vitamin E, desferrioxamine, melatonin, glutathione and vitamin C, respectively. The synergistic actions of melatonin with vitamin C, vitamin E, and glutathione were systematically investigated. When melatonin was combined with vitamin E, glutathione, or vitamin C, the protective effects against iron-induced lipid peroxidation were dramatically enhanced. Even though melatonin was added at very low concentrations, it still showed synergistic effects with other antioxidants at certain concentrations. Furthermore, melatonin not only reversed the pro-oxidative effects of vitamin C, but its efficacy in reducing lipid peroxidation was improved when it was combined with pro-oxidative concentrations of vitamin C. The results provide new information in terms of the possible pharmacological use of the combination of melatonin and classical antioxidants to treat free radical-related conditions.  相似文献   

8.
The presence of cyanobacterial toxins in drinking and recreational waters represents a potential public health risk. Microcystin-LR (MC-LR) is a potent cyclic heptapeptide hepatotoxin produced by the blue-green alga Microcystis aeruginosa. Chemoprotectant studies have indicated that membrane-active antioxidants such as vitamin E may offer protection against microcystin toxicity. This study investigated the effect of vitamin E supplementation on microcystin toxicity in mouse liver. Groups of mice were fed vitamin E supplements (8.33 or 33.3 U/mouse/day) for 4 weeks, with intraperitoneal doses of MC-LR extract (70% LD(50)) every 3 days from day 8. The potential benefits of vitamin E were evaluated based on lipid peroxidation, alanine transaminase (ALT), and glutathione S-transferase (GST) levels. Vitamin E supplementation at 33.3 U/mouse/day offered some protection against lipid peroxidation induced by repeated exposure to MC-LR extract and limited both the toxin-induced increase in ALT leakage and decrease in GST activity. Vitamin E supplementation at 66.6 U/mouse/day significantly increased the time to death and reduced the increase in liver percentage body weight induced in mice given a lethal dose challenge of MC-LR extract. Therefore, vitamin E, taken as a dietary supplement, may have a protective effect against chronic exposure to MC-LR.  相似文献   

9.
1. The mechanisms of the liver damage produced by three glutathione (GSH)-depleting agents, bromobenzene, allyl alcohol and diethyl maleate, were investigated.

2. With each toxin liver necrosis was accompanied by lipid peroxidation that developed only after severe depletion of GSH.

3. Changes in antioxidant systems by α-tocopherol (vitamin E) and ascorbic acid were studied. A decrease in the hepatic level of vitamin E, and a change in the redox state of vitamin C (increase in oxidized over reduced form) were evident whenever extensive lipid peroxidation developed. However, in the case of bromobenzene intoxication these alterations preceded lipid peroxidation, and may be an index of oxidative stress leading to subsequent membrane damage.

4. Experiments carried out with vitamin E-deficient or supplemented diets indicated that pathological phenomena occurring as a consequence of GSH depletion depend on hepatic levels of vitamin E. In vitamin E-deficient animals, lipid peroxidation and liver necrosis appeared earlier than in animals fed the control diet. In animals fed a vitamin E-supplemented diet, bromobenzene and allyl alcohol had only limited toxicity, and diethyl maleate none, in spite of similar hepatic GSH depletion. Thus, vitamin E may largely modulate the expression of toxicity by GSH-depleting agents.  相似文献   

10.
1. The mechanisms of the liver damage produced by three glutathione (GSH)-depleting agents, bromobenzene, allyl alcohol and diethyl maleate, were investigated. 2. With each toxin liver necrosis was accompanied by lipid peroxidation that developed only after severe depletion of GSH. 3. Changes in antioxidant systems by alpha-tocopherol (vitamin E) and ascorbic acid were studied. A decrease in the hepatic level of vitamin E, and a change in the redox state of vitamin C (increase in oxidized over reduced form) were evident whenever extensive lipid peroxidation developed. However, in the case of bromobenzene intoxication these alterations preceded lipid peroxidation, and may be an index of oxidative stress leading to subsequent membrane damage. 4. Experiments carried out with vitamin E-deficient or supplemented diets indicated that pathological phenomena occurring as a consequence of GSH depletion depend on hepatic levels of vitamin E. In vitamin E-deficient animals, lipid peroxidation and liver necrosis appeared earlier than in animals fed the control diet. In animals fed a vitamin E-supplemented diet, bromobenzene and allyl alcohol had only limited toxicity, and diethyl maleate none, in spite of similar hepatic GSH depletion. Thus, vitamin E may largely modulate the expression of toxicity by GSH-depleting agents.  相似文献   

11.
In vitro effect of methanol on folate-deficient rat hepatocytes   总被引:1,自引:0,他引:1  
Methanol is primarily metabolized by oxidation to formaldehyde and then to formic acid. These processes are accompanied by formation of superoxide anion and hydrogen peroxide. This paper reports the in vitro antioxidant effect of vitamin E on isolated hepatocytes of folic acid deficient rats rendered so as to emulate a human hepatocyte model. These hepatocytes were treated with 320 microM of methanol per million cells and incubated for 30 min. The microsomal fraction of these hepatocytes showed a decreased level of superoxide dismutase (SOD), with increase in lipid peroxidation (LPO) shown by increase in recorded levels of malondialdehyde (MDA). Catalase activity was shown to be increased. Levels of reduced glutathione (GSH) were decreased and the activity of glutathione peroxidase (GSH-Px) and of glutathione reductase (GSSG-R) were not altered. The hepatocytes of folate deficient rats pretreated with vitamin E, when subjected to methanol treatment, showed no significant change in SOD levels and a significant decrease in MDA levels. The catalase activity in this group of animals showed a highly significant decrease. These animals had normal levels of GSH, while a significant fall in GSH-Px and GSSG-R levels were observed. These results suggest that Vitamin E exerts a protective effect on hepatocytes by acting as a free radical scavenger, proving its usefulness in treating methanol toxicity.  相似文献   

12.
The effect of the vitamin E status of membranes on the balance between pro- and antioxidant activity of ascorbic acid was studied in microsomes from rat heart, kidney and liver. Lipid peroxidation was initiated by 5 microM ferrous ions, in combination with amounts of ascorbic acid ranging from 0-4 mM. Lipid peroxidation was assessed after 1 h of incubation as production of thiobarbituric acid reactive material. It was found that the vitamin E status of the microsomal membranes had little effect on the balance between pro- and antioxidant activity of vitamin C. The sensitivity of the membranes to ferrous ions/ascorbic acid-induced lipid peroxidation, however, was highly dependent on the vitamin E content of the membranes. Vitamin E depletion, in combination with different ascorbic acid concentrations, showed that vitamin E deficiency is not an incontestable model system for enhanced sensitivity to lipid peroxidation in all organs.  相似文献   

13.
Chronic alcohol consumption is directly related to the induction of liver damage. The continuous use of ethanol induces the isoenzyme cytochrome P450CYP2E1, which promotes the formation of free radicals, resulting in lipid peroxidation. Among the main antioxidants are vitamin E, reduced glutathione (GSH), vitamin C, and beta-carotene. beta-Carotene has antioxidant activity per se, with a probable protective effect against different types of cancer. However, some studies have shown an increased number of cancer cells when beta-carotene is administered in the presence of chronic ethanol ingestion. On this basis, the objective of the present study was to assess the effect of beta-carotene supplementation on rats chronically treated with a hydroalcoholic solution by determining the levels of vitamin E, beta-carotene, GSH, and thiobarbituric acid reactive species (TBARS). Both the plasma and liver concentrations of beta-carotene were higher in the supplemented groups. Plasma vitamin E levels were decreased in the control group and liver vitamin E levels were significantly decreased (p < 0.05) in all groups compared to basal levels. GSH levels were increased over basal values in the group supplemented with beta-carotene for 14 days. TBARS values were increased as much as four-fold in the control group at 14 days, and declined again at 28 days, whereas they were increased in the supplemented group, with the increase remaining until the end of the experiment. The study indicates that beta-carotene had no beneficial effect as an antioxidant on rats submitted to chronic alcohol intake, and could be act as prooxidant when administered with ethanol.  相似文献   

14.
The order of antioxidant effectiveness of low concentrations of vitamin E analogues, in preventing cumene hydroperoxide-induced hepatocyte lipid peroxidation and cytotoxicity, was 2,2,5,7,8-pentamethyl-6-hydroxychromane (PMC) > troglitazone > Trolox C > alpha-tocopherol > gamma-tocopherol > delta-tocopherol. However, vitamin E analogues, including troglitazone at higher concentrations, induced microsomal lipid peroxidation when oxidized to phenoxyl radicals by peroxidase/H2O2. Ascorbate or GSH was also cooxidized, and GSH cooxidation by vitamin E analogue phenoxyl radicals was also accompanied by extensive oxygen uptake and oxygen activation. When oxidized by nontoxic concentrations of peroxidase/H2O2, vitamin E analogues except PMC also caused hepatocyte cytotoxicity, lipid peroxidation, and GSH oxidation. The prooxidant order of vitamin E analogues in catalyzing hepatocyte cytotoxicity, lipid peroxidation, and GSH oxidation was troglitazone > Trolox C > delta-tocopherol > gamma-tocopherol > alpha-tocopherol > PMC. A similar order of effectiveness was found for GSH cooxidation or microsomal lipid peroxidation but not for ascorbate cooxidation. Except for troglitazone, the toxic prooxidant activity of vitamin E analogues was therefore inversely proportional to their antioxidant activity. The high troglitazone prooxidant activity could be a contributing factor to its hepatotoxicity. We have also derived equations for three-parameter quantitative structure-activity relationships (QSARs), which described the correlation between antioxidant and prooxidant activity of vitamin E ananlogues and their lipophilicity (log P), ionization potential (E(HOMO)), and dipole moment.  相似文献   

15.
In pemphigus vulgaris, the increased production of reactive oxygen species from activated neutrophils decreases concentrations of antioxidant vitamins and enzymes in plasma and red blood cells (RBC), resulting in oxidative stress. We compared lipid peroxidation, a measure of reactive oxygen species production, antioxidant vitamins, reduced glutathione (GSH), glutathione peroxide (GSH-Px), and catalase enzyme activity in blood samples obtained from 18 nonsmoking pemphigus vulgaris patients and an equal number of age- and gender-matched, healthy control subjects. Plasma and RBC lipid peroxidation levels (malonyl dialdehyde) were significantly higher (p < 0.05) in pemphigus vulgaris patients than in control subjects. Significantly lower concentrations of plasma antioxidant vitamins (vitamin E and beta-carotene) and vitamin A (p < 0.001), antioxidant enzymes (catalase in RBC and plasma, GSH-Px in RBC [p < 0.05]), and respective GSH activities in both RBC and plasma (p < 0.05 and p < 0.01) were found in pemphigus vulgaris patients than in control subjects. GSH-Px in plasma did not change significantly. The results provide evidence for a potential role of increased lipid peroxidation and peroxidation and decreased antioxidants in pemphigus vulgaris by its inflammatory character.  相似文献   

16.
ABSTRACT

The antioxidant defense system dramatically controls hepatocellular carcinoma induced by N.-nitrosodiethylamine (NDEA). In order to assess the anticarcinogenic activity of a methanol extract of Caesalpinia bonducella. (MECB) leaves containing flavonoids and triterpenoids, the antioxidant defense system has been evaluated. The effect of MECB on lipid peroxidation end-product malondialdehyde (MDA), enzymatic antioxidants such as superoxide dismutase (SOD) and catalase (CAT), and nonenzymatic antioxidants glutathione (GSH), vitamin E, and vitamin C levels were analyzed in the liver of control and experimental animals. Serum was also analyzed for transaminase activity (SGOT and SGPT), alkaline phosphatase (SALP), bilirubin, total protein, and uric acid. Depletion of all these antioxidants was recorded in cancer conditions. These deleterious effects are controlled by the administration of MECB. After drug administration, there was a marked increase in antioxidant levels and a dramatic decrease in lipid peroxidation levels. MECB also produced a protective effect by decreasing the activity of serum enzymes, bilirubin, and increased the protein and uric acid levels. From the above results, it can be concluded that the observed anticarcinogenic properties of MECB may also be explained by its strong antioxidant capacity and capability to induce an in vivo. antioxidant system.  相似文献   

17.
Phosgene, widely used in industrial processes, can cause life-threatening pulmonary edema and acute lung injury. One mechanism of protection against phosgene-induced lung injury may involve the use of antioxidants. The present study focused on dietary supplementation in mice using n-propyl gallate (nPG)--a gallate acid ester compound used in food preservation--and vitamin E. Five groups of male mice were studied: group 1, control-fed with Purina rodent chow 5002; group 2, fed 0.75% nPG (w/w) in 5002; group 3, fed 1.5% nPG (w/w) in 5002; group 4 fed 1% (w/w) vitamin E in 5002; and group 5, fed 2% (w/w) vitamin E also in 5002. Mice were fed for 23 days. On day 23 mice were exposed to 32 mg m-3 (8 ppm) phosgene for 20 min (640 mg. min m-3) in a whole-body exposure chamber. Survival rates were determined at 12 and 24 h. In mice that died within 12 h, the lungs were removed and lung wet weights, dry weights, wet/dry weight ratios, lipid peroxidation (thiobarbituric acid reactive substances, TBARS) and glutathione (GSH) were assessed. Vitamin E had no positive effect on any outcome measured. There was no significant difference between 1.5% nPG and any parameter measured or survival rate compared with 5002 + phosgene. However, dietary treatment with 0.75% nPG significantly increased survival rate (P 相似文献   

18.
Nicotine, a pharmacologically active substance in tobacco, has been identified as a major risk factor for lung diseases. In the present study, we evaluated the protective effects of curcumin on tissue lipid peroxidation and antioxidants in nicotine-treated Wistar rats. Lung toxicity was induced by subcutaneous injection of nicotine at a dose of 2.5 mg/kg (5 days a week, for 22 weeks). Curcumin (80 mg/kg) was given simultaneously by intragastric intubation for 22 weeks. The enhanced level of tissue lipid peroxides in nicotine-treated rats was accompanied by a significant decrease in the levels of ascorbic acid, vitamin E, reduced glutathione, glutathione peroxidase, superoxide dismutase and catalase. Administration of curcumin significantly lowered the level of lipid peroxidation and enhanced the antioxidant status. The results of the present study suggest that curcumin exerts its protective effect against nicotine-induced lung toxicity by modulating the extent of lipid peroxidation and augmenting antioxidant defense system.  相似文献   

19.
In this study, the antioxidant protection of ascorbic acid (AA) supplementation during different unfed periods (24, 48, 120 h) was determined with blood lipid peroxidation level (thiobarbituric acid reactive substances, TBARS) and compared with plasma antioxidant sulfydryl group (RSH) content. Weight loss was induced by increasing the unfed period together with vitamin C supplementation. Blood AA levels decreased by starvation but increased by vitamin C supplementation. RSH content in plasma also decreased with the unfed period; these decreases became apparent by vitamin C supplementation. TBARS formation increased significantly by AA supplementation in the 120-h starvation period.  相似文献   

20.
In this study, the effect of combination of vitamin C (ascorbic acid), vitamin E (alpha -tocopherol), and selenium (sodium selenate) on ethanol-induced liver and intestine injury in rats was investigated. The ethanol-induced injury was produced by the administration of 1 ml of absolute ethanol to each rats. Animals received vitamin C (250 mg/kg), vitamin E (250 mg/kg), and sodium selenate (Se) (0.5 mg/kg) for 3 days; 1 h after the final antioxidant administration, they were sacrificed. Lipid peroxidation and glutathione levels, catalase (CAT), lactate dehydrogenase (LDH), superoxide dismutase (SOD), and glutathione peroxidase (GP(x)) activities were determined in liver and intestine tissues. Myeloperoxidase (MPO), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT) were determined in liver tissue. Also, CAT activity, urea, creatinine, uric acid, and total lipid levels were determined in serum samples. In the ethanol group, serum urea, creatinine, uric acid, and total lipid levels; liver and intestine LDH; liver MPO, AST, ALP, ALT, and GGT activities; and liver and intestine LPO levels increased, whereas serum CAT activity, liver and intestine GSH levels, and CAT, SOD, and GP(x) activities decreased. On the other hand, treatment with vitamin C, vitamin E, and Se reversed these effects. As a result of these findings, we can say that the combination of vitamin C, vitamin E, and selenium has a protective effect on ethanol-induced changes in lipid peroxidation, glutathione levels, and antioxidant enzyme activities in liver and intestine tissues, and in some serum parameters of rats.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号